Modern medicine depends increasingly on the use of medications for the treatment and control of medical conditions. The use of drugs is particularly diverse and heavy in the health care institution environment, where the most serious medical conditions are treated. Today, the typical pharmacy needs to maintain a stock of approximately 3,000 to 5,000 different medications to meet routine demands.
The most important aspect of any institutional pharmacy operation is the delivery of medications from the pharmacy to the patient. Traditionally, prescriptions were filled by the institutional pharmacy and delivered to the dispensing station. As the use of drugs and the number of orders increased, however, this system became too slow in delivery time to the patient. Efforts to speed up delivery resulted in moving the drugs to where the patient was. This method was known as "floor stock." In the floor stock system, miniature pharmacies were created at each nursing station where the nurses interpreted the physician's order and dispensed the drugs without the aid of a pharmacist. This speeded up the drug delivery, but it created errors because the nursing staff lacked proper pharmaceutical training. These drug errors were of a magnitude that they became the primary reason to develop the "unit dose" system. In this system the institutional pharmacy made hourly deliveries to each nursing station.
By returning control of dispensing to pharmacy, error reduction was documented. Cost savings were such that the expense of the medication carts and other equipment were easily justified in concept. In practice, however, it soon became apparent that magnum increases in pharmacy staff were required to accomplish drug distribution every hour, on the hour. To solve this problem, institutions went to the "cart exchange" system. In the cart exchange system, the institutional pharmacy would stock a drug dispensing cart for each dispensing station on a periodic basis. Since most institutional administrators balked at increases in pharmacy staffing, the pharmacy was forced to reduced the number of cart deliveries to one delivery every 24 hours. This allowed the pharmacy to operate without the full staffing required by pure unit dose. It did, however, create a more serious problem of increasing medication errors. The cart exchange often required the pharmacy to guess what medications would be needed by any particular patient in the next 24 hours. Where a medication requirement was unanticipated, there was often an unacceptable delay in getting the needed medication to the patient. This often resulted in the "borrowing" of drugs from other patients, which in turn caused a loss of drug administration accuracy. The cart exchange system of unit dose drug distribution is basically an error producing method of handling drugs. Of the errors generated, 80 percent are errors of omission. This leaves 20 percent as errors of commission. The obvious reason for this is that pharmacy is required to load the carts 24 hours in advance. Since 30 percent of the total orders change daily, the carts have a built in error factor. Another problem is then created in that all of the drug omissions in the carts must now be supplied to the nursing stations. The majority of the new orders (omissions) are requested between 7.gtoreq.8 A.M., 12-1 P.M. and 7-9 P.M.
The average time required to deliver the first dose of medication ranges from 2.5 to 4 hours. If the first dose was to be given at 8 A.M. and it was not ordered until 7 A.M. then the chances of the patient getting a late dose or missing it entirely are very good.
Another problem has been the ability to provide 24 hour pharmacy service to remote hospitals, nursing homes, and clinics from a central location.